An image acquisition device, an eye refractive distribution measurement device, and a measurement method.

Abstract

This invention discloses an image acquisition device, an ocular refractive distribution measurement device, and a measurement method thereof. Based on the refractive condition of the fovea of ​​each subject's eye, the imaging system is adjusted to an initial adjustment state. Then, according to preset scanning parameters, the imaging system is controlled to perform refractive distribution measurement starting from the initial adjustment state. In this way, the scanning range of the imaging system can be automatically adjusted for different subjects' individual conditions, greatly shortening the ocular refractive distribution measurement time and improving measurement efficiency.

Description

Technical Field

[0001] This invention relates to the field of ocular refractive power measurement technology, and in particular to an image acquisition device, an ocular refractive distribution measurement device, and a measurement method. Background Technology

[0002] The imaging area of ​​the retina includes the macula and the peripheral region. Refractive errors (myopia and hyperopia) are commonly referred to as focusing errors based on the macula. If the focusing point is in front of the macula, it's called myopia; if it's behind the macula, it's called hyperopia. The refractive value measured at the macula is commonly referred to as the eye's diopter. Refractive values ​​measured at different locations within the peripheral region of the macula are called peripheral refractive errors, which exhibit an irregular distribution. Figure 1 This represents the actual measured refractive distribution results for different tested eyes. Among them, the value of the fovea (the value inside the small circle in the center) is the refractive value at the macula, which represents the refractive error state of the eye. A positive value indicates hyperopia, a negative value indicates myopia, and a value of zero indicates emmetropia.

[0003] Several techniques exist for measuring peripheral refractive errors, including those employing a focusing technique. A drawback of this technique is that the imaging system needs to perform a wide-range zoom scan during measurement to ensure that the refractive ranges of different eyes being tested are within the zoom range. For example... Figure 2 As shown, the refractive ranges of the eyes of different individuals A, B, and C are different. The zoom imaging system needs to cover the refractive ranges of the three eyes (A, B, and C) during zoom scanning (hereinafter referred to as zoom scanning). Due to the large zoom scanning range, the measurement system needs to acquire images for a long time. During the measurement process, the eyes need to maintain a stable eye position and pupil size for a long time and cannot blink. This requires a high degree of cooperation from the subject and results in low measurement efficiency. Summary of the Invention

[0004] The main objective of this invention is to automatically adjust the scanning range of the imaging system according to the individual circumstances when measuring refractive distribution for different subjects, thereby greatly shortening the measurement time and improving measurement efficiency.

[0005] To achieve the above objectives, the present invention provides an image acquisition device, comprising:

[0006] An imaging system, comprising a first imaging lens group and at least one image acquisition unit;

[0007] Light source projection module; and,

[0008] The control device acquires the refractive value at the macula of the eye, controls the imaging system to be in an initial adjustment state based on the refractive value, and continuously performs state adjustment scanning from the initial adjustment state, so that the image acquisition device acquires image sequences of different defocus degrees of the fundus; and obtains the ocular refractive distribution based on the image sequences.

[0009] Optionally, the light source projection module includes a first mode for projecting measurement light and a second mode for projecting illumination light, wherein the measurement light is a ring light and the illumination light is a surface light.

[0010] Optionally, the refractive value at the macula of the eye is determined in the first mode.

[0011] Optionally, the first imaging lens group includes a zoom lens group, and the state adjustment scan is to adjust the position of the at least one image acquisition device and / or adjust the focal length of the zoom lens group.

[0012] Optionally, the light source projection module includes a first annular illumination module and an adjustable aperture.

[0013] Optionally, the light source projection module includes:

[0014] A first light source module is used to project measurement light to form a first mode; and,

[0015] The second light source module is used to project illumination light to form a second mode.

[0016] Optionally, it also includes a fixation module, which is synchronized with the at least one image acquisition device.

[0017] Optionally, the fixation module includes a reflector disposed on one side of the main optical axis and corresponding to the beam splitter, and a second imaging lens group and the fixation module disposed sequentially away from the reflector along a direction parallel to the main optical axis.

[0018] Optionally, the pattern projection device includes a fixed light source and a light-transmitting pattern plate disposed between the fixed light source and the second imaging lens group.

[0019] Optionally, the projection light source includes a projection light source element, a first condenser lens group, and a homogenizer.

[0020] Optionally, the light source projection module includes a first annular illumination module corresponding to the hollow reflector and an adjustment aperture disposed between the first annular illumination module and the hollow reflector, wherein the working mode of the adjustment aperture can be switched to form the first mode and the second mode.

[0021] Optionally, the light source projection module further includes a first beam splitter, which is configured corresponding to the hollow reflector;

[0022] The first light source module is positioned on the side of the first beam splitter facing the hollow reflector;

[0023] The second light source module is positioned on the side of the first beam splitter that is opposite to the hollow reflector.

[0024] Optionally, the first light source module includes a first light source and an aperture module disposed between the first light source and the first beam splitter; and / or,

[0025] The second light source includes a second ring light source and a second condenser lens disposed between the second ring light source and the first beam splitter.

[0026] Optionally, the focusing unit includes a position adjuster for adjusting the position of the image acquisition unit.

[0027] Optionally, the image acquisition device includes:

[0028] A first image acquisition device, configured corresponding to the first imaging lens group, is used to acquire images from the first imaging lens group, and to synchronously adjust the connection between the first image acquisition device and the fixation module; and...

[0029] The second image acquisition device is configured corresponding to the first imaging lens group and is used to acquire images on the first imaging lens group;

[0030] The position adjuster is configured as a plurality of such adjusters, and the plurality of position adjusters include:

[0031] A first position adjuster synchronously adjusts the positions of the imaging system and the fixation module; and...

[0032] The second position adjuster adjusts the second image acquisition device.

[0033] Optionally, the first imaging lens group includes a zoom lens group, and the focusing unit adjusts the focal length of the imaging system by adjusting the zoom lens group.

[0034] The present invention also provides an ocular refractive distribution measurement device, including the above-mentioned image acquisition device; and a computing unit, which obtains the ocular refractive distribution based on the image sequence.

[0035] The present invention also provides a method for measuring ocular refractive distribution, characterized by comprising the following steps:

[0036] (1) Obtain the refractive value at the fovea of ​​the fundus;

[0037] (2) Based on the refractive value at the fovea of ​​the fundus, the imaging system is put into the initial adjustment state;

[0038] (3) Starting from the initial adjustment state, the focal length of the imaging system is adjusted to obtain image sequences of different defocus degrees of the fundus;

[0039] (4) Obtain the eye refractive distribution based on the image sequence.

[0040] The image acquisition device, ocular refractive distribution measurement equipment, and measurement method provided by this invention, during testing, first adjust the state of the imaging system to an initial adjustment state according to the refractive condition of the subject's fovea. Then, starting from this initial adjustment state, the state adjustment scan of the imaging system is performed to achieve the measurement of ocular refractive distribution. In this way, the scanning range of the imaging system can be automatically adjusted according to the individual situation of different subjects, which greatly shortens the measurement time of ocular refractive distribution, reduces the difficulty of subject cooperation during ocular refractive distribution measurement, and improves the efficiency and accuracy of ocular refractive distribution measurement. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0042] Figure 1 A schematic diagram illustrating the refractive range of different individuals' eyes;

[0043] Figure 2 A schematic diagram of the refractive accommodation range of existing technologies:

[0044] Figure 3 A schematic diagram of a first embodiment of the image acquisition device provided by the present invention;

[0045] Figure 4 for Figure 3 A schematic diagram of the refractive adjustment range of the image acquisition device during testing;

[0046] Figure 5 for Figure 3 Two operating states of an embodiment of the adjustment aperture;

[0047] Figure 6 for Figure 3 Two operating states of another embodiment of the adjustment aperture.

[0048] Figure 7 for Figure 4The optical path diagram of the adjustment aperture in the first mode;

[0049] Figure 8 for Figure 4 The optical path diagram of the adjustment aperture in the second mode;

[0050] Figure 9 A schematic diagram of a second embodiment of the image acquisition device provided by the present invention;

[0051] Figure 10 A schematic diagram of a third embodiment of the image acquisition device provided by the present invention;

[0052] Figure 11 for Figure 10 A schematic diagram of the operation of the first light source module in the diagram;

[0053] Figure 12 for Figure 11 A schematic diagram of the optional structure one for the second aperture;

[0054] Figure 13 for Figure 11 A schematic diagram of the optional structure two of the second aperture.

[0055] Explanation of icon numbers:

[0056]

[0057]

[0058] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0059] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0060] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0061] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0062] This invention proposes an image acquisition device; please refer to [link / reference]. Figures 3 to 8 ,include:

[0063] 11. Eyepiece assembly; 12. Beam splitter; 33. Fixing module; 5. Light source projection module; 6. Focusing unit; 7. Imaging system; 8. Control device.

[0064] The light source projection module 5 includes a first mode for projecting measurement light and a second mode for projecting illumination light. The measurement light is specifically a ring light, which can be a ring composed of multiple points or a band, and its wavelength can be infrared. The illumination light is specifically a surface light, which, unlike ring illumination, can form overall illumination in a certain area, such as a circular illumination area or a rectangular illumination area.

[0065] The imaging system includes a first imaging lens group 14 and at least one image acquisition unit 2;

[0066] The focusing unit includes a first position adjuster 41 and a second position adjuster 42. The first position adjuster 41 is connected to the first imaging lens group 14 and / or at least one image acquisition device 2, and is used to change the position of the first imaging lens group 14 and / or at least one image acquisition device 2. The second position adjuster 42 is connected to the fixation module 33, and is used to change the position of the fixation module 33.

[0067] The control device 6 acquires the refractive value at the macula of the eye and controls the imaging system to be in an initial adjustment state based on the refractive value; starting from the initial adjustment state, the imaging system is controlled to continuously perform state adjustment scanning, so that the image acquisition device acquires image sequences of different defocus degrees of the fundus; and the eye refractive distribution is obtained based on the image sequences.

[0068] For controlling the state of the imaging system, the control device 6 is electrically connected to the focusing unit. By controlling the focusing unit, the position of the first imaging lens group 14 and / or at least one image acquisition device 2 is adjusted to control and scan the focal length of the imaging system.

[0069] The control device is also electrically connected to the light source projection module 5 and is used to control the projection mode of the light source projection module 5.

[0070] The refractive value at the macula of the eye can be obtained by receiving external data or by direct measurement. The sources of external data can include medical consultation, searching local or online databases, searching remote servers, etc.

[0071] After acquiring the image sequence from the image acquisition unit, the control device 6 obtains the eye refractive distribution through image processing and calculation.

[0072] Fixation module 33 is used to guide the line of sight and to relax the eye being tested, putting it in a state without refractive accommodation.

[0073] The beam-splitting element 12 is a dichroic mirror, but it can also be a beam splitter, a glass plate, etc.

[0074] In an embodiment of the present invention, the fixation module 33 includes a fixation light source 331 and a light-transmitting pattern plate 332 disposed between the fixation light source 331 and the second imaging lens group 32. Light is projected from the fixation light source 331 onto the light-transmitting pattern plate 332, forming a corresponding pattern after passing through the light-transmitting pattern plate 332. The light then sequentially passes through the second imaging lens group 32 and the reflecting mirror 31, is reflected to the beam splitter 12, and then reflected by the beam splitter 12 to the eyepiece group 11, and finally projected onto the fundus of the subject. The fixation light source 331 can be an LED light source structure, and the light-transmitting pattern plate 332 can be a semi-transparent pattern plate. Specifically, the fixation light source includes a fixation light source element 331a, a first condenser lens group 331b, and a light homogenizer 331c. The fixation light source element 331a is an LED, etc. The first condenser lens group 331b and the light homogenizer 331c ensure that the light can uniformly reach all areas of the light-transmitting pattern plate 332.

[0075] Alternatively, the fixation module can also take the form of a non-patterned element, such as a bright spot, as long as it serves to guide the eye.

[0076] In one embodiment of the present invention, the light source projection module 5 includes a first annular illumination module 5a corresponding to the hollow reflector 13, and an adjustment aperture 5b disposed between the first annular illumination module 5a and the hollow reflector 13. The adjustment aperture 5b has two modes, one of which is a working mode, i.e., a pinhole mode, such as... Figure 7 As shown, in this mode, light passing through the pinhole, as indicated by the solid line in the figure, travels through the optical path and forms a bright ring on the fundus, thus forming the first mode. This mode is used to determine the initial adjustment state of the imaging system. The second mode is the non-working mode, i.e., the light-passing mode, as shown... Figure 8As shown, in this mode, aperture 3 does not obstruct the retinal illumination light; the shadowed area is illuminated by light emitted from a ring light source, which can illuminate the entire retina, providing surface lighting for capturing retinal images, thus forming the second mode. Adjusting aperture 5b can... Figure 5 The form of switching positions in the middle can also be used for Figure 6 The mechanically variable aperture diaphragm of the central rotating blade type can also have its aperture shape controlled by an LCD screen, thus enabling the switching between two light emission modes. This invention does not limit the specific method for adjusting the aperture size of the adjustable aperture 5b.

[0077] The present invention also proposes an ocular refractive distribution measurement device, including the above-mentioned image acquisition device; and a computing unit, which obtains the ocular refractive distribution based on the image sequence.

[0078] The measurement method of the eye refractive distribution measurement device is as follows:

[0079] First, the fixed image pattern or fixed image target formed by the fixed light source 331 is converged into the human eye through the second imaging lens group 32, the reflecting mirror 31, the beam splitter 12, and the eyepiece group 11, forming an image on the retina and guiding the direction of the human eye's gaze. The light reflected from the fundus is converged through the eyepiece group 11, the beam splitter 12, and passes through the light-transmitting hole in the middle of the hollow reflecting mirror 13, and the first imaging lens group 14, forming an image at the image acquisition device 2. The conjugate surface of the fixed image pattern in the human eye is located in front of the conjugate surface of the image acquisition device 2 in the human eye (the direction closer to the anterior segment is considered forward).

[0080] The control device 6 independently controls the position controllers 41 and 42, keeping the relative positions of the fixation module and the image acquisition unit 1 constant, thus ensuring that the positional difference between their conjugate surfaces in the human eye remains consistent. In this way, when the image acquisition unit 1 is conjugate with the macula of the human eye, the translucent pattern will be imaged at a fixed distance in front of the retina, presenting a pattern with a fixed degree of blur. This fogging effect avoids refractive accommodation in the human eye.

[0081] Next, the control device 6 sets the aperture 5b to the working mode, i.e., the pinhole mode. The ring illumination light generated by the ring light source 5a is sequentially converged into the eye through the hollow reflector 13, the beam splitter 12, and the eyepiece assembly 11, forming a bright ring on the fundus. Figure 11 As shown, due to the different axial lengths of different refractive eyes, the size of the bright spot projected onto the fundus will vary. Figure 11 The bright spot sizes A1B1, A2B2, and A3B3 correspond to moderate myopia, emmetropia, and hyperopia, respectively. The bright ring at the fundus is reflected from the retina and emitted into the eye. It then converges through the eyepiece group 11, passes through the beam splitter 12, passes through the light-transmitting hole in the middle of the hollow mirror 13, and the first imaging mirror group 14, and is imaged at the image acquisition device 2.

[0082] The control device 6 calculates the coarse refractive value D1 of the macula based on the size of the bright spot in the fundus acquired by the image acquisition device 2 at the current position, and controls the image acquisition device 2 to position D1. Position D1 refers to the image plane position conjugate with the fundus when the macula refractive value is D1. The fixation module 33 is then controlled to position D1', which refers to the position where a certain myopic defocus is formed in the fundus when the macula refractive value is D1. Then, the control device 6 calculates the macular refractive value D2 based on the size of the bright spot in the fundus acquired by the image acquisition device 2 at position D1. If the difference between D2 and D1 is large, the fixation module 33 moves to position D2', and the image acquisition device 2 moves to position D2 to acquire an image. The above steps are repeated until the deviation between D2 and D1 measured in two consecutive measurements is less than or equal to a certain threshold xD, finally obtaining an accurate macula refractive value, thereby putting the imaging system into the initial adjustment state. The initial adjustment state is the state in which the imaging system presents a clear image of the macula, which is achieved by adjusting the focal length of the first imaging lens group 14 and / or the position of at least one image acquisition unit 2.

[0083] Next, the control device 6 controls the aperture 5b to change from pinhole mode to light-through mode, illuminating the entire fundus with surface light generated by the light source projection module 5. Then, under the control of the control device 6, the first imaging lens group 14 or the image acquisition unit 2 of the imaging system performs state-adjustment scanning with scanning parameters, starting from the initial adjustment state. Simultaneously, it acquires image sequences of different positions on the retina under different adjustment states. In this way, the state-adjustment scanning range can be reduced, and the time for measuring the ocular refractive distribution can be shortened.

[0084] Specifically, the control device 6 determines the refractive accommodation range and strategy for measuring the eye's refractive distribution based on the obtained macular refractive value, and initializes the initial accommodation state of the focusing unit. Scanning parameters, including scanning range and step size, are obtained based on statistical analysis of data from a large number of subjects. Assuming the measured macular refractive value is Q, and the refractive accommodation range is Q-ΔQ1 to Q+ΔQ2, the initial accommodation state is set to correspond to the Q value, or to any value between Q-ΔQ1, Q+ΔQ2, or Q-ΔQ1 and Q+ΔQ2. ΔQ1 and ΔQ2 can be obtained through statistical analysis. For the refractive accommodation strategy, the refractive accommodation interval is selected as ΔD. The accommodation direction can start from Q-ΔQ1 and end at Q+ΔQ2, or start from Q+ΔQ2 and end at Q-ΔQ1, or start from a value between Q-ΔQ1 and Q+ΔQ2 and scan sequentially in the direction of increasing or decreasing Q to complete the refractive accommodation within the range of Q-ΔQ1 to Q+ΔQ2. The refractive adjustment can be achieved by continuously changing the focal length of the first imaging lens group and / or continuously changing the position of the image acquisition unit.

[0085] Finally, the image sensor 2 transmits all the fundus image sequences to the operation unit. The operation unit calculates the refractive power distribution of the entire retina of the human eye based on the state of the imaging system and the obtained image sequences, and outputs the calculation results to the display for display. The refractive power distribution of the entire retina is composed of different refractive power values at multiple different positions on the retina. The refractive power value changes with different positions and is represented in polar coordinates as E(r,θ). Taking a certain position on the retina (such as the center of the macula) as the origin, r is the polar radius, that is, the diameter direction, representing different field angles, 0 < r < r1, where r1 is the maximum measured field angle, such as 20° to 70°, and θ is the polar angle, 0 ≤ θ ≤ 2π, representing the azimuth angle, or the circumferential direction. The refractive power distribution of the naked eye is irregular in both the radial and circumferential directions.

[0086] As Figure 9 shown, in another embodiment of the present invention, different from the above embodiment, the image collector 2 is set to two, including:

[0087] The first image collector 2a is used for the first mode measurement of the light source projection module 5, that is, receiving the reflected light of the fundus when the annular light illuminates the fundus; and,

[0088] The second image collector 2b is used for the second mode measurement of the light source projection module 5, that is, receiving the reflected light of the fundus when the surface light illuminates the fundus.

[0089] In addition, in another embodiment of the present invention, different from the above embodiment, the position regulator 4 is set to multiple, including:

[0090] The first position regulator 41 sets the first image collector 2a and the fixation module 33 on it at the same time; and the second position regulator 42 adjusts the position of the second image collector 2b. By setting the first image collector 2a and the fixation module 33 on the first position regulator 41 at the same time, the positions of the first image collector 2a and the fixation module 3 set to be constant, and synchronous adjustment is performed, so that the position difference of the conjugate planes of the two in the human eye will always remain consistent. In this way, when the first image collector 2a is conjugate with the macula of the human eye, the image on the fixation module 33 will be imaged at a fixed distance in front of the retina of the human eye, presenting a pattern with a fixed degree of blurring. This fogging effect can avoid the human eye from generating refractive adjustment.

[0091] It can be understood that there can be three position regulators, which are respectively used to adjust the fixation module, the first image collector 2a, and the second image collector 2b.

[0092] The measurement method for the device differs from the above embodiment in that a first image acquisition device 2a is used to measure the macula to determine the initial adjustment state of the imaging system. A second image acquisition device 2b is used to measure the refractive distribution of the retina. Specifically, based on the measurement results of the macula, the imaging system consisting of the second image acquisition device 2b and the first imaging lens group is adjusted to the initial adjustment state. Then, starting from the initial adjustment state, the eye refractive distribution is measured using scanning parameters. This reduces the state adjustment scanning range and shortens the time for measuring the eye refractive distribution.

[0093] like Figures 10 to 13 As shown, another embodiment of the invention differs from the above embodiments in that the light source projection module 5 specifically includes:

[0094] A first light source module 51, corresponding to the hollow reflector 13, is used to project ring light onto the hollow reflector 13 to form the first pattern; and,

[0095] The second light source module 52 is provided corresponding to the hollow reflector 13 and is used to project surface light onto the hollow reflector 13 to form the second mode.

[0096] That is, in this embodiment, the first light source module 51 and the second light source module 52 generate illumination light of different shapes respectively, so as to adjust the light output mode of the two.

[0097] Specifically, in this embodiment, the light source projection module 5 further includes a first beam splitter 53, which is disposed corresponding to the hollow reflector 13. The first light source module 51 is disposed on the side of the first beam splitter 53 facing the hollow reflector 13, and the second light source module 52 is disposed on the side of the first beam splitter 53 facing away from the hollow reflector 13. In this way, by setting the first beam splitter 53, the first light source module 51 and the second light source module 52 can project light onto the hollow reflector 13 from different positions.

[0098] More specifically, in this embodiment, the first light source module 51 includes a first light source 511 and an aperture module 512 disposed between the first light source 511 and the first beam splitter 53. The first light source 511 includes an LED lamp, and the aperture module 512 includes a first aperture 512a and a second aperture 512b. The first aperture 512a is provided with a small aperture hole, and the second aperture 512b is provided with an annular aperture hole. The light emitted from the first light source 511 passes through the small aperture hole of the first aperture 512a and is arranged in an annular shape to form an annular light source, and then passes through the annular aperture hole on the second aperture 512b and is emitted.

[0099] More specifically, in this embodiment, the second light source includes a second ring light source 521 and a second condenser lens 522 disposed between the second ring light source 521 and the first beam splitter 53. Obviously, the second light source does not have to be a ring light source, but can also be an array light source, such as an array LED.

[0100] In an embodiment of the present invention, the first imaging lens group 14 includes a zoom lens group. The focusing unit adjusts the state of the imaging system by changing the focal length of the zoom lens group or changing the position of the image acquisition unit, or simultaneously changes the position of the image acquisition unit 2 and the focal length of the zoom lens group to adjust the focal length of the imaging system.

[0101] Based on the above-described device, the present invention also provides a method for measuring ocular refractive distribution, characterized by comprising the following steps:

[0102] (1) Obtain the refractive value at the fovea of ​​the fundus; the acquisition method can be achieved by receiving external data or by direct measurement. The source of external data can be consultation, searching local or online databases, searching remote servers, etc.

[0103] (2) Based on the refractive value at the fovea of ​​the fundus, the imaging system is put into the initial adjustment state; the initial adjustment state includes the initial adjustment position of the image acquisition device, or the initial focal length state of the first imaging lens group using the zoom lens group.

[0104] (3) Starting from the initial adjustment state, the imaging system is subjected to state adjustment scanning to obtain image sequences of different defocus degrees of the fundus; the focal length of the imaging system is adjusted according to the preset refractive adjustment parameters, and fundus images are acquired at each focal length adjustment to finally obtain image sequences of all fundus images of different defocus degrees; the refractive adjustment parameters include the refractive adjustment range and step size; the refractive adjustment parameters are obtained through a large amount of data statistics.

[0105] (4) The processing unit obtains the ocular refractive distribution based on the image sequence. For multiple target locations in the fundus, the optimal image sharpness for each target location is obtained based on the image sequence. Then, the focal length and refractive value of the corresponding target location are obtained based on the optimal image sharpness. Finally, the ocular refractive distribution is synthesized based on the obtained refractive values ​​of multiple target locations. The multiple target locations are different locations in the fundus determined according to measurement needs.

[0106] Step (1) specifically also includes:

[0107] (1.1) The controller controls the light source projection module to operate in a first mode to project a ring light onto the fundus;

[0108] (1.2) The imaging system acquires annular light images reflected from the fovea of ​​the fundus;

[0109] (1.3) The controller obtains the foveal refractive value of the fundus based on the size change of the ring light image.

[0110] Optionally, step (3) further includes:

[0111] Before the state-adjustment scan, the controller controls the light source projection module to operate in the second mode to project surface light onto the fundus. Subsequently, during the state-adjustment scan, the imaging system continuously acquires images formed by the reflection of surface light from the fundus, thereby obtaining an image sequence.

[0112] In measuring ocular refractive distribution, this invention first adjusts the imaging system to an initial accommodation state based on the refractive condition of the subject's fovea. Then, starting from this initial accommodation state, the imaging system is scanned to achieve ocular refractive distribution measurement. This reduces the scanning range of the imaging system, shortens the refractive accommodation time, reduces the difficulty of subject cooperation during ocular refractive distribution measurement, and improves the efficiency and accuracy of ocular refractive distribution measurement.

[0113] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. An image acquisition device, characterized in that, include: An imaging system, comprising a first imaging lens group and at least one image acquisition unit; Light source projection module; as well as, The control device acquires the refractive value at the macula of the eye, controls the imaging system to be in an initial adjustment state based on the refractive value, and controls the imaging system to continuously perform state adjustment scanning starting from the initial adjustment state, so that the image acquisition device acquires image sequences of different defocus degrees of the fundus.

2. The apparatus as claimed in claim 1, characterized in that, The light source projection module includes a first mode for projecting measurement light and a second mode for projecting illumination light.

3. The apparatus as described in claim 2, characterized in that, The refractive value at the macula of the eye is determined in the first mode.

4. The apparatus as claimed in claim 1, characterized in that, The first imaging lens group includes a zoom lens group.

5. The apparatus as described in claim 4, characterized in that, The state adjustment scan is used to adjust the position of the at least one image acquisition device and / or adjust the focal length of the zoom lens group.

6. The apparatus as claimed in claim 2, characterized in that, The light source projection module includes a first ring illumination module and an adjustable aperture; Alternatively, the light source projection module includes: A first light source module is used to project measurement light to form a first mode; And a second light source module for projecting illumination light to form a second mode.

7. The apparatus as claimed in claim 1, characterized in that, It also includes a fixed-view module.

8. The apparatus as claimed in claim 7, characterized in that, The fixed-view module is synchronized with the at least one image acquisition device.

9. An eye refractive distribution measurement device, characterized in that, The device includes the image acquisition apparatus according to any one of claims 1-8; and a processing unit for obtaining the ocular refractive distribution based on the image sequence.

10. A method for measuring ocular refractive distribution, characterized in that, Includes the following steps: (1) Obtain the refractive value of the macula in the fundus; (2) Based on the refractive value of the macula in the fundus, the imaging system is put into the initial adjustment state; (3) Starting from the initial adjustment state, the imaging system is continuously scanned to obtain image sequences of different defocus degrees of the fundus; (4) Obtain the eye refractive distribution based on the image sequence.

Images